scholarly journals Revised nomenclature and SNP barcode for Mycobacterium tuberculosis lineage 2

2021 ◽  
Vol 7 (11) ◽  
Author(s):  
Yuttapong Thawornwattana ◽  
Surakameth Mahasirimongkol ◽  
Hideki Yanai ◽  
Htet Myat Win Maung ◽  
Zhezhe Cui ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Type Species ◽  
Classification Scheme ◽  
Snp Markers ◽  
Drug Resistant ◽  
Fine Scale ◽  
Content Type ◽  
Classification Schemes ◽  
Disease Epidemiology ◽  
Lineage 2

Mycobacterium tuberculosis (Mtb) lineage 2 (L2) strains are present globally, contributing to a widespread tuberculosis (TB) burden, particularly in Asia where both prevalence of TB and numbers of drug resistant TB are highest. The increasing availability of whole-genome sequencing (WGS) data worldwide provides an opportunity to improve our understanding of the global genetic diversity of Mtb L2 and its association with the disease epidemiology and pathogenesis. However, existing L2 sublineage classification schemes leave >20 % of the Modern Beijing isolates unclassified. Here, we present a revised SNP-based classification scheme of L2 in a genomic framework based on phylogenetic analysis of >4000 L2 isolates from 34 countries in Asia, Eastern Europe, Oceania and Africa. Our scheme consists of over 30 genotypes, many of which have not been described before. In particular, we propose six main genotypes of Modern Beijing strains, denoted L2.2.M1–L2.2.M6. We also provide SNP markers for genotyping L2 strains from WGS data. This fine-scale genotyping scheme, which can classify >98 % of the studied isolates, serves as a basis for more effective monitoring and reporting of transmission and outbreaks, as well as improving genotype-phenotype associations such as disease severity and drug resistance. This article contains data hosted by Microreact.

scholarly journals Genetic Diversity of Multi- and Extensively Drug-Resistant Mycobacterium tuberculosis Isolates in the Capital of Iran, Revealed by Whole-Genome Sequencing

2018 ◽  
Vol 57 (1) ◽  
Author(s):  
Farzam Vaziri ◽  
Thomas A. Kohl ◽  
Hasan Ghajavand ◽  
Mansour Kargarpour Kamakoli ◽  
Matthias Merker ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Recent Transmission ◽  
Mdr Tb ◽  
Lineage 2

ABSTRACT The emergence and spread of multidrug resistant (MDR) Mycobacterium tuberculosis complex (MTBC) strains is a critical global health problem. Between 2014 and 2018, 606 MTBC strains were isolated from 13,892 suspected pulmonary tuberculosis (TB) patients in Tehran, Iran, including 16 (2.6%) MDR-TB cases. A combination of phenotypic and genotypic methods (whole-genome sequencing) was employed for the identification of additional drug resistances and strain-to-strain genetic distances as a marker for recent transmission events. MDR and extensively drug-resistant (XDR) TB cases were almost exclusively infected by lineage 2/Beijing strains (14/16, P < 0.001). We further showed that recent transmission and/or recent introduction of lineage 2/Beijing strains contribute to high XDR-TB rates among all MDR-TB cases and should be considered an emerging threat for TB control in Tehran. In addition, the extensive pre-existing drug resistance profiles of MDR/XDR strains will further challenge TB diagnostics in the region.

scholarly journals Genome analyses of 174 strains of Mycobacterium tuberculosis provide insight into the evolution of drug resistance and reveal potential drug targets

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Helianthous Verma ◽  
Shekhar Nagar ◽  
Shivani Vohra ◽  
Shubhanshu Pandey ◽  
Devi Lal ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Target ◽  
Drug Targets ◽  
Type Species ◽  
Close Association ◽  
Drug Resistant ◽  
Potential Drug ◽  
Sequence Alignments ◽  
Content Type ◽  
Link Type

Mycobacterium tuberculosis is a known human pathogen that causes the airborne infectious disease tuberculosis (TB). Every year TB infects millions of people worldwide. The emergence of multi-drug resistant (MDR), extensively drug resistant (XDR) and totally drug resistant (TDR) M. tuberculosis strains against the first- and second-line anti-TB drugs has created an urgent need for the development and implementation of new drug strategies. In this study, the complete genomes of 174 strains of M. tuberculosis are analysed to understand the evolution of molecular drug target (MDT) genes. Phylogenomic placements of M. tuberculosis strains depicted close association and temporal clustering. Selection pressure analysis by deducing the ratio of non-synonymous to synonymous substitution rates (dN/dS) in 51 MDT genes of the 174 M . tuberculosis strains led to categorizing these genes into diversifying (D, dN/dS>0.70), moderately diversifying (MD, dN/dS=0.35–0.70) and stabilized (S, dN/dS<0.35) genes. The genes rpsL, gidB, pncA and ahpC were identified as diversifying, and Rv0488, kasA, ndh, ethR, ethA, embR and ddn were identified as stabilized genes. Furthermore, sequence similarity networks were drawn that supported these divisions. In the multiple sequence alignments of diversifying and stabilized proteins, previously reported resistance mutations were checked to predict sensitive and resistant strains of M. tuberculosis . Finally, to delineate the potential of stabilized or least diversified genes/proteins as anti-TB drug targets, protein–protein interactions of MDT proteins with human proteins were analysed. We predict that kasA (dN/dS=0.29), a stabilized gene that encodes the most host-interacting protein, KasA, should serve as a potential drug target for the treatment of TB.

scholarly journals Evolution and emergence of multidrug-resistant Mycobacterium tuberculosis in Chisinau, Moldova

2021 ◽  
Vol 7 (8) ◽  
Author(s):  
Tyler S. Brown ◽  
Vegard Eldholm ◽  
Ola Brynildsrud ◽  
Magnus Osnes ◽  
Natalie Levy ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Population Size ◽  
Type Species ◽  
Sequence Data ◽  
Multidrug Resistant ◽  
Capital City ◽  
Whole Genome Sequence ◽  
Drug Resistant ◽  
Content Type ◽  
Link Type

The evolution and emergence of drug-resistant tuberculosis (TB) has been studied extensively in some contexts, but the ecological drivers of these two processes remain poorly understood. This study sought to describe the joint evolutionary and epidemiological histories of a novel multidrug-resistant Mycobacterium tuberculosis strain recently identified in the capital city of the Republic of Moldova (MDR Ural/4.2), where genomic surveillance of drug-resistant M. tuberculosis has been limited thus far. Using whole genome sequence data and Bayesian phylogenomic methods, we reconstruct the stepwise acquisition of drug resistance mutations in the MDR Ural/4.2 strain, estimate its historical bacterial population size over time, and infer the migration history of this strain between Eastern European countries. We infer that MDR Ural/4.2 likely evolved (via acquisition of rpoB S450L, which confers resistance to rifampin) in the early 1990s, during a period of social turmoil following Moldovan independence from the Soviet Union. This strain subsequently underwent substantial population size expansion in the early 2000s, at a time when national guidelines encouraged inpatient treatment of TB patients. We infer exportation of this strain and its isoniazid-resistant ancestral precursor from Moldova to neighbouring countries starting as early as 1985. Our findings suggest temporal and ecological associations between specific public health practices, including inpatient hospitalization of drug-resistant TB cases from the early 2000s until 2013, and the evolution of drug-resistant M. tuberculosis in Moldova. These findings underscore the need for regional coordination in TB control and expanded genomic surveillance efforts across Eastern Europe.

scholarly journals Comparison of In Vitro Activity and MIC Distributions between the Novel Oxazolidinone Delpazolid and Linezolid against Multidrug-Resistant and Extensively Drug-Resistant Mycobacterium tuberculosis in China

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Zhaojing Zong ◽  
Wei Jing ◽  
Jin Shi ◽  
Shu'an Wen ◽  
Tingting Zhang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Novel Mutation ◽  
Multidrug Resistant ◽  
23S Rrna ◽  
Drug Resistant ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Significant Difference ◽  
Mdr Tb

ABSTRACT Oxazolidinones are efficacious in treating mycobacterial infections, including tuberculosis (TB) caused by drug-resistant Mycobacterium tuberculosis. In this study, we compared the in vitro activities and MIC distributions of delpazolid, a novel oxazolidinone, and linezolid against multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) in China. Additionally, genetic mutations in 23S rRNA, rplC, and rplD genes were analyzed to reveal potential mechanisms underlying the observed oxazolidinone resistance. A total of 240 M. tuberculosis isolates were included in this study, including 120 MDR-TB isolates and 120 XDR-TB isolates. Overall, linezolid and delpazolid MIC90 values for M. tuberculosis isolates were 0.25 mg/liter and 0.5 mg/liter, respectively. Based on visual inspection, we tentatively set epidemiological cutoff (ECOFF) values for MIC determinations for linezolid and delpazolid at 1.0 mg/liter and 2.0 mg/liter, respectively. Although no significant difference in resistance rates was observed between linezolid and delpazolid among XDR-TB isolates (P > 0.05), statistical analysis revealed a significantly greater proportion of linezolid-resistant isolates than delpazolid-resistant isolates within the MDR-TB group (P = 0.036). Seven (53.85%) of 13 linezolid-resistant isolates were found to harbor mutations within the three target genes. Additionally, 1 isolate exhibited an amino acid substitution (Arg126His) within the protein encoded by rplD that contributed to high-level resistance to linezolid (MIC of >16 mg/liter), compared to a delpazolid MIC of 0.25. In conclusion, in vitro susceptibility testing revealed that delpazolid antibacterial activity was comparable to that of linezolid. A novel mutation within rplD that endowed M. tuberculosis with linezolid, but not delpazolid, resistance was identified.

scholarly journals Urgent Implementation in a Hospital Setting of a Strategy To Rule Out Secondary Cases Caused by Imported Extensively Drug-Resistant Mycobacterium tuberculosis Strains at Diagnosis

2016 ◽  
Vol 54 (12) ◽  
pp. 2969-2974 ◽  
Author(s):  
Laura Pérez-Lago ◽  
Miguel Martínez-Lirola ◽  
Sergio García ◽  
Marta Herranz ◽  
Igor Mokrousov ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
High Risk ◽  
Primary Cultures ◽  
Hospital Setting ◽  
Drug Resistant ◽  
Nucleotide Polymorphisms ◽  
Content Type ◽  
Extensively Drug Resistant ◽  
Incident Cases ◽  
Rule Out

Current migratory movements require new strategies for rapidly tracking the transmission of high-risk importedMycobacterium tuberculosisstrains. Whole-genome sequencing (WGS) enables us to identify single-nucleotide polymorphisms (SNPs) and therefore design PCRs to track specific relevant strains. However, fast implementation of these strategies in the hospital setting is difficult because professionals working in diagnostics, molecular epidemiology, and genomics are generally at separate institutions. In this study, we describe the urgent implementation of a system that integrates genomics and molecular tools in a genuine high-risk epidemiological alert involving 2 independent importations of extensively drug resistant (XDR) and pre-XDR BeijingM. tuberculosisstrains from Russia into Spain. Both cases involved commercial sex workers with long-standing tuberculosis (TB). The system was based on strain-specific PCRs tailored from WGS data that were transferred to the local node that was managing the epidemiological alert. The optimized tests were available for prospective implementation in the local node 33 working days after receiving the primary cultures of the XDR strains and were applied to all 42 new incident cases. An interpretable result was obtained in each case (directly from sputum for 27 stain-positive cases) and corresponded to the amplification profiles for strains other than the targeted pre-XDR and XDR strains, which made it possible to prospectively rule out transmission of these high-risk strains at diagnosis.

Biochemical and functional characterization of Mycobacterium tuberculosis ketol-acid reductoisomerase

Microbiology ◽  
2021 ◽  
Vol 167 (9) ◽  
Author(s):  
Nirbhay Singh ◽  
Anu Chauhan ◽  
Ram Kumar ◽  
Sudheer Kumar Singh
Keyword(s):  
Amino Acids ◽  
Mycobacterium Tuberculosis ◽  
Type Species ◽  
Low Ph ◽  
Stress Conditions ◽  
Starvation Stress ◽  
Content Type ◽  
E Coli ◽  
Link Type

Branched-chain amino acids (BCAAs) are essential amino acids, but their biosynthetic pathway is absent in mammals. Ketol-acid reductoisomerase (IlvC) is a BCAA biosynthetic enzyme that is coded by Rv3001c in Mycobacterium tuberculosis H37Rv (Mtb-Rv) and MRA_3031 in M. tuberculosis H37Ra (Mtb-Ra). IlvCs are essential in Mtb-Rv as well as in Escherichia coli . Compared to wild-type and IlvC-complemented Mtb-Ra strains, IlvC knockdown strain showed reduced survival at low pH and under low pH+starvation stress conditions. Further, increased expression of IlvC was observed under low pH and starvation stress conditions. Confirmation of a role for IlvC in pH and starvation stress was achieved by developing E. coli BL21(DE3) IlvC knockout, which was defective for growth in M9 minimal medium, but growth could be rescued by isoleucine and valine supplementation. Growth was also restored by complementing with over-expressing constructs of Mtb-Ra and E. coli IlvCs. The E. coli knockout also had a survival deficit at pH=5.5 and 4.5 and was more susceptible to killing at pH=3.0. The biochemical characterization of Mtb-Ra and E. coli IlvCs confirmed that both have NADPH-dependent activity. In conclusion, this study demonstrates the functional complementation of E. coli IlvC by Mtb-Ra IlvC and also suggests that IlvC has a role in tolerance to low pH and starvation stress.

scholarly journals Bazedoxifene Suppresses Intracellular Mycobacterium tuberculosis Growth by Enhancing Autophagy

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Qi Ouyang ◽  
Kehong Zhang ◽  
Dachuan Lin ◽  
Carl G. Feng ◽  
Yi Cai ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
New Host ◽  
Drug Resistant Tuberculosis ◽  
Content Type ◽  
Receptor Modulator ◽  
Resistant Tuberculosis ◽  
Negative Side Effects

ABSTRACT Tuberculosis (TB) is still the leading killer caused by Mycobacterium tuberculosis infection. There is a clear need for new treatment strategy against TB. It has been reported that tamoxifen, known as a selective estrogen receptor modulator (SERM), exhibits antimycobacterial activity and inhibits M. tuberculosis growth in macrophages. However, it remains unknown whether such antimicrobial activity is a general property of all SERMs and how it works. In this study, we identified that bazedoxifene (BZA), a newer SERM, inhibits intracellular M. tuberculosis growth in macrophages. BZA treatment increases autophagosome formation and LC3B-II protein expression in M. tuberculosis-infected macrophages. We further demonstrated that the enhancement of autophagy by BZA is dependent on increased reactive oxygen species (ROS) production and associated with phosphorylation of Akt/mTOR signaling. In summary, our data reveal a previously unappreciated antimicrobial function of BZA and suggest that future investigation focusing on the mechanism of action of SERMs in macrophages may lead to new host-directed therapies against TB. IMPORTANCE Since current strategies for the treatment of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) have low efficacy and highly negative side effects, research on new treatments including novel drugs is essential for curing drug-resistant tuberculosis. Host-directed therapy (HDT) has become a promising idea to modulate host cell responses to enhance protective immunity against pathogens. Bazedoxifene (BZA), which belongs to a new generation of SERMs, shows the ability to inhibit the growth of M. tuberculosis in macrophages and is associated with autophagy. Our findings reveal a previously unrecognized antibacterial function of BZA. We propose that the mechanism of SERMs action in macrophages may provide a new potential measure for host-directed therapies against TB.

scholarly journals Genome Sequencing of Polydrug-, Multidrug-, and Extensively Drug-Resistant Mycobacterium tuberculosis Strains from South India

2019 ◽  
Vol 8 (12) ◽  
Author(s):  
Sivakumar Shanmugam ◽  
Narender Kumar ◽  
Dina Nair ◽  
Mohan Natrajan ◽  
Srikanth Prasad Tripathy ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
South India ◽  
Sequence Data ◽  
Whole Genome ◽  
Drug Resistant ◽  
Resistance Mutations ◽  
Content Type ◽  
Extensively Drug Resistant

The genomes of 16 clinical Mycobacterium tuberculosis isolates were subjected to whole-genome sequencing to identify mutations related to resistance to one or more anti-Mycobacterium drugs. The sequence data will help in understanding the genomic characteristics of M. tuberculosis isolates and their resistance mutations prevalent in South India.

scholarly journals Whole-Genome Sequencing of Mycobacterium tuberculosis Provides Insight into the Evolution and Genetic Composition of Drug-Resistant Tuberculosis in Belarus

2016 ◽  
Vol 55 (2) ◽  
pp. 457-469 ◽  
Author(s):  
Kurt R. Wollenberg ◽  
Christopher A. Desjardins ◽  
Aksana Zalutskaya ◽  
Vervara Slodovnikova ◽  
Andrew J. Oler ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
De Novo ◽  
Acquired Resistance ◽  
Multiple Infections ◽  
Drug Resistant ◽  
Genetic Composition ◽  
Hiv Patients ◽  
Treatment Protocols ◽  
Content Type ◽  
Phenotypic Resistance

ABSTRACTThe emergence and spread of drug-resistantMycobacterium tuberculosis(DR-TB) are critical global health issues. Eastern Europe has some of the highest incidences of DR-TB, particularly multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB. To better understand the genetic composition and evolution of MDR- and XDR-TB in the region, we sequenced and analyzed the genomes of 138M. tuberculosisisolates from 97 patients sampled between 2010 and 2013 in Minsk, Belarus. MDR and XDR-TB isolates were significantly more likely to belong to the Beijing lineage than to the Euro-American lineage, and known resistance-conferring loci accounted for the majority of phenotypic resistance to first- and second-line drugs in MDR and XDR-TB. Using a phylogenomic approach, we estimated that the majority of MDR-TB was due to the recent transmission of already-resistantM. tuberculosisstrains rather than repeatedde novoevolution of resistance within patients, while XDR-TB was acquired through both routes. Longitudinal sampling ofM. tuberculosisfrom 34 patients with treatment failure showed that most strains persisted genetically unchanged during treatment or acquired resistance to fluoroquinolones. HIV+ patients were significantly more likely to have multiple infections over time than HIV− patients, highlighting a specific need for careful infection control in these patients. These data provide a better understanding of the genomic composition, transmission, and evolution of MDR- and XDR-TB in Belarus and will enable improved diagnostics, treatment protocols, and prognostic decision-making.

scholarly journals Evaluation of Pyrosequencing for Detecting Extensively Drug-Resistant Mycobacterium tuberculosis among Clinical Isolates from Four High-Burden Countries

2014 ◽  
Vol 59 (1) ◽  
pp. 414-420 ◽  
Author(s):  
Kanchan Ajbani ◽  
Shou-Yean Grace Lin ◽  
Camilla Rodrigues ◽  
Duylinh Nguyen ◽  
Francine Arroyo ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
The Philippines ◽  
Drug Susceptibility Testing ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
Second Line ◽  
Additional Advantage ◽  
Content Type ◽  
Extensively Drug Resistant

ABSTRACTReliable molecular diagnostics, which detect specific mutations associated with drug resistance, are promising technologies for the rapid identification and monitoring of drug resistance inMycobacterium tuberculosisisolates. Pyrosequencing (PSQ) has the ability to detect mutations associated with first- and second-line anti-tuberculosis (TB) drugs, with the additional advantage of being rapidly adaptable for the identification of new mutations. The aim of this project was to evaluate the performance of PSQ in predicting phenotypic drug resistance in multidrug- and extensively drug-resistant tuberculosis (M/XDR-TB) clinical isolates from India, South Africa, Moldova, and the Philippines. A total of 187 archived isolates were run through a PSQ assay in order to identifyM. tuberculosis(via the IS6110marker), and to detect mutations associated with M/XDR-TB within small stretches of nucleotides in selected loci. The molecular targets includedkatG, theinhApromoter and theahpC-oxyRintergenic region for isoniazid (INH) resistance; therpoBcore region for rifampin (RIF) resistance;gyrAfor fluoroquinolone (FQ) resistance; andrrsfor amikacin (AMK), capreomycin (CAP), and kanamycin (KAN) resistance. PSQ data were compared to phenotypic mycobacterial growth indicator tube (MGIT) 960 drug susceptibility testing results for performance analysis. The PSQ assay illustrated good sensitivity for the detection of resistance to INH (94%), RIF (96%), FQ (93%), AMK (84%), CAP (88%), and KAN (68%). The specificities of the assay were 96% for INH, 100% for RIF, FQ, AMK, and KAN, and 97% for CAP. PSQ is a highly efficient diagnostic tool that reveals specific nucleotide changes associated with resistance to the first- and second-line anti-TB drug medications. This methodology has the potential to be linked to mutation-specific clinical interpretation algorithms for rapid treatment decisions.

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